Fairfield Water Hardness & Quality Report (2026)

The City of Fairfield Water Treatment Plant, located on Groh Lane adjacent to the city's Water Works Park, serves more than 44,000 customers across the Fairfield area in Butler County, Ohio. The utility draws its water supply exclusively from the Great Miami Buried Valley Aquifer via municipal wells. In 2020 alone, the treatment plant processed over 2 billion gallons of groundwater pumped from this aquifer system.

Fairfield's water originates from the Great Miami Buried Valley Aquifer, a glacial-age formation composed of sand, gravel, and clay deposits overlying Ordovician and Silurian bedrock dominated by limestone and dolomite. As precipitation infiltrates and percolates into the aquifer, it dissolves calcium and magnesium from these carbonate formations, progressively mineralizing the groundwater. This carbonate-rich geological setting is typical of southwestern Ohio's glaciated terrain and results in a consistently hard supply.

Hard water causes noticeable scale buildup on fixtures, reduced soap lathering, and potential dry skin effects. Appliances including water heaters, dishwashers, and washing machines are particularly vulnerable to mineral accumulation and reduced efficiency. A water softener is recommended to mitigate scale formation, extend appliance lifespan, and improve cleaning product effectiveness; regular descaling of appliances is also advisable. Fairfield's water quality is rated excellent with a violation score of 0.0; however, 1,4-Dioxane has been detected above health guidelines in the water supply and requires ongoing monitoring and treatment. The city publishes an annual Consumer Confidence Report detailing water quality parameters and treatment methods.